• Title/Summary/Keyword: Waste ceramic

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Status and perspectives of the advanced catalytic combustion (촉매연소의 신기술 동향)

  • Kang, Sung-Kyu
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.299-308
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    • 2003
  • This paper provides a review of the status and of the perspectives of advanced catalytic combustion for ultra clean combustion of gas turbines and for industrial combustors. The development of catalytic materials and their combustion techniques for gas turbines are briefly reported. The fuel-rich approaches to catalytic combustion are mentioned for a new technology of thermal- and fuel-NOx control. The fuel-rich catalytic combustion are also applicable to the combustor of ceramic gas turbine, and to the combustion of biomess and municipal waste sludge. Some extended technologies of combustion synthesis are introduced for the synthesis of carbon nanotube and of Perovskite combustion catalysts

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Feasibility Study on Vitrification for Rare Earth Wastes of PyroGreen Process (파이로그린공정 희토류폐기물 유리화 타당성 연구)

  • Kim, Cheon-Woo;Lee, Byeong Gwan
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.1
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    • pp.1-9
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    • 2013
  • The rare earth oxide wastes consisting of major 8 nuclides Y, La, Ce, Pr, Nd, Sm, Eu and Gd, are generated during the salt waste treatment of PyroGreen process. The final form of the rare earth is generated as the oxide state. In this study, six candidate glasses were developed to evaluate the feasibility for vitrifying the rare earth oxide wastes within the borosilicate glass system. The solubilities of the mixture of the rare earth oxide waste showed less than 25wt% at $1,200^{\circ}C$, less than 30wt% at $1,300^{\circ}C$, respectively. It means that solubility is increased with the temperature increment. The liquidus temperature of the homogeneous glass with 20wt% waste loading was determined as less than $950^{\circ}C$. In more than solubility of rare earth oxides glass, formation of rare earth-oxide-silicate crystal in glass-ceramic occurred as the secondary phase. As their viscosity at melting temperature $1,200{\sim}1,300^{\circ}C$ was less than 100 poise, electrical conductivity was higher than 1 S/cm, 20~25wt% waste loading glasses with good surface homogeneity are judged to have good operability in cold crucible induction melter. Other physicochemical properties of the developed glasses are going to be experimented in the future.

Mineralogical Analysis of Calcium Silicate Cement according to the Mixing Rate of Waste Concrete Powder (폐콘크리트 미분말 치환율에 따른 이산화탄소 반응경화 시멘트의 광물상 분석)

  • Lee, Hyang-Sun;Song, Hun
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.2
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    • pp.181-191
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    • 2024
  • In the realm of cement manufacturing, concerted efforts are underway to mitigate the emission of greenhouse gases. A significant portion, approximately 60%, of these emissions during the cement clinker sintering process is attributed to the decarbonation of limestone, which serves as a fundamental ingredient in cement production. Prompted by these environmental concerns, there is an active pursuit of alternative technologies and admixtures for cement that can substitute for limestone. Concurrently, initiatives are being explored to harness technology within the cement industry for the capture of carbon dioxide from industrial emissions, facilitating its conversion into carbonate minerals via chemical processes. Parallel to these technological advances, economic growth has precipitated a surge in construction activities, culminating in a steady escalation of construction waste, notably waste concrete. This study is anchored in the innovative production of calcium silicate cement clinkers, utilizing finely powdered waste concrete, followed by a thorough analysis of their mineral phases. Through X-ray diffraction(XRD) analysis, it was observed that increasing the substitution level of waste concrete powder and the molar ratio of SiO2 to (CaO+SiO2) leads to a decrease in Belite and γ-Belite, whereas minerals associated with carbonation, such as wollastonite and rankinite, exhibited an upsurge. Furthermore, the formation of gehlenite in cement clinkers, especially at higher substitution levels of waste concrete powder and the aforementioned molar ratio, is attributed to a synthetic reaction with Al2O3 present in the waste concrete powder. Analysis of free-CaO content revealed a decrement with increasing substitution rate of waste concrete powder and the molar ratio of SiO2/(CaO+SiO2). The outcomes of this study substantiate the viability of fabricating calcium silicate cement clinkers employing waste concrete powder.

Membrane Characteristics for Removing Particulates in PFC Wastes (PFC제염폐액 내의 미립자 제거를 위한 여과막의 특성 연구)

  • Kim Gye-Nam;Lee Sung-Yeol;Won Hui-Jun;Jung Chong-Hun;Oh Won-Zin;Park Jin-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.2
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    • pp.149-157
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    • 2005
  • PFC(Perfluorocarbon) decontamination process is one of best methods to remove hot particulate adhered at inside surface of hot cell and surface of equipment in hot cell. It was necessary to develop a particulate filtration equipment to reuse PFC solution used on PFC decontamination due to its high cost and to minimize the volume of second wastewater. Contamination characteristics of hot particulate were investigated and then a filtration process was presented to remove hot particulate in PFC solution generated through PFC decontamination process. The removal efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic(Al$_{2}$O$_{3}$ filter showed more than 95$\%$. The removal efficiency of PVDF filter was a little lower than those of other kiters at same pressure(3psi). A ceramic filter showed a higher removal efficiency with other filters, while a little lower flux rate than other filters. Due to inorganic composition, a ceramic filter was highly stable against radio nuclides in comparison with PVDF and PP membrane, which generate H$_{2}$ gas in e-radioactivity atmosphere. Therefore, the adoption of ceramic filter is estimated to be suitable for the real nitration process.

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Analysis for Water Vapour Adsorption and Desorption Performance of Waste Paper-Mulberry according to Particle Size Control (폐닥나무의 입도제어에 따른 흡·방습 특성 분석)

  • Jo, Ki-Sic;Kim, Tae-Yeon;Seo, Sung-Kwan;Lee, Oh-Kyu;Chu, Yong-Sik
    • Resources Recycling
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    • v.29 no.2
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    • pp.8-17
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    • 2020
  • In this study, adsorption and desorption characteristics of pulverized waste paper-mulberry pellet and bast fiber were measured to confirm the applicability to humidity control products. Paper-mulberry powder was classified by 710-355㎛, 355-100㎛, 100-45㎛ and less than 45㎛ and used in experiment. Specific surface area increased from 1.02㎡/g to 1.35㎡/g as the particle size decreased from 710㎛ to under 45㎛. Adsorption and desorption performance decreased in the order of 355-100㎛, 710-355㎛, 100-45㎛, less than 45㎛ and bast fiber, adsorption content on each particle sizes were 141.1g/㎡, 147.1g/㎡, 135.7g/㎡, 129.0g/㎡ and desorption content were 117.2g/㎡, 123.6g/㎡, 110.2g/㎡, 93.3g/㎡. As a result, adsorption and desorption performance of paper-mulberry powder were superior to those of the bast fiber and these phenomenon can be considered that it caused by pore distribution in pellet and damage of fiber.